USA World Sales via eBay offers the First Alert Bark Genie for $13.99 with free shipping. Except for the mentions below and other eBay sellers, that's the lowest price we could find by $6. It emits an ultrasonic sound up to 15 feet that deters barking by getting the dog's attention.
Note: Walmart and Amazon have it for $14.39. Opt for in-store pickup at Walmart or free shipping with Prime at Amazon.